Relationships among average subglottal pressure, average glottal airflow,
and glottal adduction (vocal process gap), variables related to glottal
competence, were obtained for one human subject. The data define the
pressure-flow-adduction space. Results are similar to those of a study using
excised canine larynges [Alipour et al., ``Pressure-flow relationships during
phonation as a function of adduction,'' J. Voice (in press)] especially for the
differential flow resistance as a function of adduction. For set values of
adduction, glottal flow resistance increased by about 2.5 times between
subglottal pressure values of 5 and 15 cm H[inf 2]O. At set values of subglottal
pressure, flow resistance increased by a factor of approximately 9.5 between
pressed and breathy phonation. Any particular flow resistance value does not
predict a particular adduction value due to the dependence on subglottal
pressure. However, a particular subglottal pressure, glottal flow pair appears
to predict a particular adduction level. Subglottal aerodynamic power increases
with subglottal pressure at set levels of adduction, increasing by a factor of
about 3.7 between 5 and 15 cm H[inf 2]O. For a specific value of subglottal
pressure, aerodynamic power increases as adduction decreases. [Work supported by
NIH Grant No. P60 DC00976.]